1. Technical Field
Apparatuses and methods are disclosed for dispensing a plurality of formulas volumetrically and gravimetrically using a controller having a memory that stores a plurality of formulas. The controller is linked to a plurality of pumps or conveyors, with each pump connected to a container holding one of the materials to be dispensed according to one of the formulas. The controller is also linked to a scale for measuring the amount of liquid or powder dispensed by its respective pump. The disclosed apparatuses and methods are applicable to liquid and powder ingredients.
2. Background of the Related Art
Multiple pump dispensing systems have been used in the paint industry. Specifically, such a dispensing system incorporating multiple pumps that dispense viscous fluids such as paint colorant from flexible packages is disclosed in U.S. Pat. No. 6,273,298, which is commonly owned with the present application. Typically, such systems include piston pumps mounted on a rotary turntable with each pump coupled to a flexible package containing a viscous fluid, such as a paint colorant. The turntable, pumps and packages mounted thereon, are rotated until the desired pump and package is disposed over the container to be filled. A control system is utilized to rotate the table and control the action of the pumps to control the amount of material dispensed from the packages by the pumps into the container. The linear type dispensing systems are also known.
Some currently available paint colorant dispensers utilize nutating pumps and a computer control system to control the nutating pumps. Nutating pumps have a piston which is positioned inside of a housing having a fluid inlet and a fluid outlet. The piston simultaneously slides axially and rotates inside the housing. The dispense stroke or cycle can be broken down into a number of discreet steps or segments for extremely accurate volumetric dispenses. For example, a minimum dispense can be as little as 1/256 of a fluid ounce as illustrated in U.S. Pat. Nos. 6,749,402, 6,540,486 and 6,398,515, all commonly assigned with the present application. These patents all disclose improved nutating pump technologies that are applicable to paint colorant dispensing as well as the dispensing of hair dyes, other cosmetics applications and other fluids.
Systems that dispense by volume only (i.e., not by weight) offer fast dispense times because feedback is not required. However, volumetric dispensing is not as accurate as gravimetric dispensing as air bubbles or density variations can compromise the accuracy of the amounts dispensed.
Another approach to liquid dispensing accuracy can be found in U.S. Pat. No. 5,365,722, which discloses a calibration scheme based on the ratio of impeller rotations to the weight of material dispensed. A first dispense amounting to about 95% of the target fill is carried out at a high flow rate followed by subsequent smaller dispenses at lower and lower flow rates until the target is reached. The low flow rates at the end of the dispense are necessary because a dispense in excess of the desired amount may result in the product being rejected. In short, once too much of an ingredient has been dispensed, there is no way to correct the error without rejecting that batch and starting over. However, this approach is slow as it requires multiple dispense cycles to reach the target and final cycles are carried out at very low flow rates.
Like paint, the color spectrum for hair dyes is broken down into dozens of different colors. Further, consumers having dry, normal or oily hair may require products especially formulated for their hair type. Specialized colors may be made for gray hair as opposed to more youthful hair. Coloring products may also be customized for curly hair, thin hair, afro, etc. Mixing ratios of the colorant and developer can vary greatly depending upon the desired effect. Therefore, in addition to the rainbow of shades that are necessary to meet public demand, stores are confronted with the significant problem of trying to stock all of the colors for the various hair types.
To address this problem, point-of-sale hair dye dispensing machines have been developed. One such machine is disclosed in U.S. Publication No. 2005/0087545, which is commonly owned with the present application. The machine includes a plurality of containers for storing various colorants or dye intermediates and developer solutions that typically contain an oxidizer (e.g., hydrogen peroxide).
Similar to the hair dye problem, not all cosmetic products are universally applicable. Consumers having dry, oily or normal skin may require treatment products especially formulated for their particular condition. Hair products including shampoos, conditioners, hair dyes and permanent wave solutions are all quite sensitive to individual characteristics of the treated hair. No generic formula fits all types. Even more complicated are color cosmetics. A rainbow of shades is necessary to meet public demand. Stores find it a significant problem to stock all possible variations of a particular color cosmetic. One type of multiple formula liquid dispenser is disclosed in the commonly assigned U.S. Pat. No. 6,935,386.
European regulations are becoming increasingly hostile to volatile organic components (VOCs). Because many liquid ingredients of paints, cosmetics and hair dyes contain VOCs, manufacturers and retailers are turning to powder ingredient and using water as a primary solvent. Therefore, powder dispensing systems have been developed. Co-pending U.S. application Ser. Nos. 10/841,275 and 11/100,360 disclose multiple powder dispensing systems.
The software or algorithms used to accurately dispense liquids or powders volumetrically, gravimetrically or a combination thereof tend to be complicated and require frequent calibration. As electronic scales become necessary when accuracy is paramount, electronic scales are slow operating devices and their use can increase dispense times. Further, the consumer, often with the help of a sales technician, uses the controller and software to choose the desired formulation. This process can be tedious and time consuming as the controller will require the consumer to answer numerous questions when determining the characteristics of the product to be dispensed. Then, after a formulation is chosen, the machine must execute the selected formulation, dispense the desired volume of said ingredient and then repeat the procedure for each ingredient of the selected formulation. Whether the dispense is volumetric, gravimetric or a combination of the two, the slow dispense process in combination with the selection process results in the entire operation taking several minutes or longer.
Therefore, to satisfy the needs of today's time pressured and time conscious consumers, an improved dispensing methodology that provides for faster dispense times for multiple ingredient formulations where the ingredients may be liquid or powder or a combination of liquids and powders.